Looks like I missed a lot. I probably stopped paying attention between the "Nerconomicon War" and the "Destruction of the Originator". Which means I would say the Naucean Ascension would be around there.

Obviously you have read nothing from before your time then. He is one of the, if not the, most famous and influential characters of the Golden Age. Not knowing who he is is like not knowing Kind Arthur. He is a ubiquitous figurehead in our RP lore.

Seriously Badger, even Lush knows about him, so I'd say it's not so much a case of Axon being obscure, as you not paying attention.